Abstract

The aim of the study was to determine the effect of waste water discharge on the fresh
water quality for Msimbazi river in Dar es Salaam Tanzania. This river has heavily
polluted due to effluents from domestic usage, industries and other human activities.
The problems associated with discharging waste water into the river include
eutrophication, disease eruption due to increase of various pathogens, environmental
pollution and death of animals due to chemicals found in the river. Samples were
collected between the periods of October to November 2014 to determine the different
parameters. Laboratory analyses were performed in Ubungo Maji. Statistical analysis
show that several parameters are significantly higher (p<0.01) that is permissible
levels: colour (478.25, p=0.0004), DO (p=0.004), turbidity (79.25NTU, p=0.007), EC
(13975ms/cm, p= 0.0009), nitrate (23mg/l, p=0.017 ), BOD (103.17mg/l. p=0.015),
TDS (7895.13,mg/l, p=0.0012) COD (203.34mg/l, p=0.0114) and Sulphate
(583.68mg/l p=0.042). However pH (98.8, p=0.898), temperature (24.430C, p=0.84),
phosphate (0.627mg/l, p=0.505) were within the required discharge limit. Salender
Bridge showed higher value of waste water pollution than Vingunguti. Higher value
of pollution could be attributed with effluents discharge from domestic and industrial
activities. From this study it can be concluded that waste water treatment
mismanagement of industrial wastes and lack of environmental education are the
main factors contribute to the effluent pollution in the study area. Further research is
recommended on the determination of other parameters which were not covered in the
study in different parts of Msimbazi river particularly heavy metals and
environmental interaction.